<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        ul li {
            list-style: none;
            width: 200px;
            height: 100px;
            text-align: center;
            line-height: 100px;
        }

        .item1 {
            background-color: rgb(225, 108, 57);
        }

        .item2 {
            background-color: rgb(67, 220, 143);
        }

        .item3 {
            background-color: rgb(83, 192, 238);
        }


        ul {
            margin: 0;
            padding: 0;
            display: flex;
        }

        li {
            /* flex-grow: 0;
      flex-shrink: 0;
      flex-basis: 100px; */
            /* flex: 1 0 100px; */
        }


        /* .item2{
      order: 0;
      flex: 2;
    } */
        .item4 {
            background: #000;
            width: 50px;
            height: 50px;
            align-self: flex-start;
        }
    </style>
</head>

<body>
    <ul>
        <li class="item1">1</li>
        <li class="item2">2</li>
        <li class="item3">3</li>
        <li class="item4"></li>
    </ul>
</body>

</html>